This specification relates to three dimensional (3D) printing or additive manufacturing, such as fused deposition modeling (FDM).
FDM using extruded polymer filament has evolved rapidly and is extremely useful for creating reasonably accurate three dimensional objects quickly. Current FDM printing is typically accomplished by forcing a solid plastic feedstock through a heated nozzle with smaller diameter than the original feedstock. The filament is liquefied before or as it passes through the constriction in the nozzle, and the feed pressure causes material to be extruded with a cross section approximately equal to the nozzle exit.